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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 MVVvb9t3ZZm+4+zk3KvJQE03y1iaUfq7uxl1LkxFWNrPOVms01q0SKsaLF3BzcAa
 crLk96G7Uuo/6i/8n+gZuw==

<SEC-DOCUMENT>0001127602-10-022902.txt : 20100913
<SEC-HEADER>0001127602-10-022902.hdr.sgml : 20100913
<ACCEPTANCE-DATETIME>20100913112530
ACCESSION NUMBER:		0001127602-10-022902
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100512
FILED AS OF DATE:		20100913
DATE AS OF CHANGE:		20100913

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			HANSON THOMAS L
		CENTRAL INDEX KEY:			0001209098

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-09894
		FILM NUMBER:		101068540

	MAIL ADDRESS:	
		STREET 1:		5924 OAK HOLLOW DR
		CITY:			MC FARLAND
		STATE:			WI
		ZIP:			53558

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ALLIANT ENERGY CORP
		CENTRAL INDEX KEY:			0000352541
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRIC & OTHER SERVICES COMBINED [4931]
		IRS NUMBER:				391380265
		STATE OF INCORPORATION:			WI
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		4902 NORTH BILTMORE LANE
		STREET 2:		SUITE 1000
		CITY:			MADISON
		STATE:			WI
		ZIP:			53718-2148
		BUSINESS PHONE:		608-458-3311

	MAIL ADDRESS:	
		STREET 1:		4902 NORTH BILTMORE LANE
		STREET 2:		SUITE 1000
		CITY:			MADISON
		STATE:			WI
		ZIP:			53718-2148

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	INTERSTATE ENERGY CORP
		DATE OF NAME CHANGE:	19980427

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	WPL HOLDINGS INC
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>form4a.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2010-05-12</periodOfReport>

    <dateOfOriginalSubmission>2010-05-19</dateOfOriginalSubmission>

    <issuer>
        <issuerCik>0000352541</issuerCik>
        <issuerName>ALLIANT ENERGY CORP</issuerName>
        <issuerTradingSymbol>LNT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001209098</rptOwnerCik>
            <rptOwnerName>HANSON THOMAS L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>PO BOX 14720</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MADISON</rptOwnerCity>
            <rptOwnerState>WI</rptOwnerState>
            <rptOwnerZipCode>53708-0720</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>1</isOfficer>
            <officerTitle>VP, CAO and Treasurer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-05-12</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2010-05-17</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>I</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>31.91</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3384.5905</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By 401(k) Plan</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This discretionary transaction was omitted from the reporting person's original Form 4.</footnote>
        <footnote id="F2">Reflects 401(k) holdings as of this filing date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ F. J. Buri</signatureName>
        <signatureDate>2010-09-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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